Variable-speed mechanism.



R. M. RUSK. VARIABLE SPEED MECHANISM. I

APPLICATION FILED MAR 20,1911. 1,043,629. Patented Nov. 5, 1912.

4 SHEETS-SHEET 1.

Fig.1.

INVENTOR ATTORNEYS COLUMBIA PLANOORAPH Kim-WASHINGTON, D. c

R. M. RUGK. VARIABLE SPEED MECHANISM. APPLICATION FILED MAR.20,1911.

1,043,629. Patented Nov. 5, 1912.

4 SHEETS-SHEET 2.

ATTORNEYS COLUMBIA PLANOGRAPH 0.. WASHINGTON. D. c.

R. M. RUOK.

. VARIABLE SPEED MECHANISM.

APPLICATION FILED MAR.20,1911.

1,043,629. I Patented Nov. 5, 1912.

4 SHEETSSHEET 3.

W W A owl :10"

R. M. RUGK.

VARIABLE SPEED MEGHANISM.

APPLICATION FILED MAR.20,1911.

1,043,629, Patnted Nov. 5, 1912.

4 SHEETS-SHEET 4.

COLUMBIA PLANOORAPM $0., WASHINGTON. D. C

RICHARD MATTHEWS BUCK, OF LONDON, ENGLAND.

VARIABLE-SPEED MECHANISM.

Specification of Letters Patent.

Patented Nov. 5,1912.

Application filed March 20, 1911. Serial No. 615,528.

To all whom it may concern."

Be it known that I, RICHARD MATTHEWS Boon, a subject of the King ofGreat Britain, and resident of 44 Thurloe Square, South Kensington,London, S. W., England, have invented certain new and usefulImprovements in Variable Speed Mechanism, of which the following is aspecification.

This invention relates to variable-speed mechanism of the kind whereinrotary motion is transmitted at different velocities alternatively atwill through the medium of two shafts parallel to one another and eachcarrying a plurality of toothed wheels turning together as one andhaving difierent diameters so as to be adapted to mesh, alternativelywith one another, with the respective wheels of reciprocal diameter onthe other shaft, the one set of wheels being stationary lengthwise ofits shaft while the other is slidable relatively thereto in order topermit of the ratio of transmission being varied by changing the pair ofwheels which for the time being are in mesh with one another.

The primary object of the present inven tion is to provide means for sotiming the changes of speed relatively to the speed of a member whichrotates at a constant velocity, as to enable the bringing into operationof the various pairs of change-wheels alternatively, to be effectedwithout the necessity of exerting any appreciable manual effort, andWithout the occurrence of the Violent shocks (and consequent risk ofinjury to the teeth) which are commonly experienced when, as has beenthe usual practice hitherto, ordinary clash-in gearing is employed, thatis to say gearing wherein, for the purpose of bringing a pair of wheelsinto mesh with one another by a lateral movement, the teeth of the onewheel (which is slidably mounted) are pressed laterally against those ofthe other wheel (whose position lengthwise of its shaft is stationary)until the revolution of one or of both wheels has brought the teeth ofthe one wheel opposite to the tooth-gaps of the other wheel so as topermit of the continued pressure causing the slidable wheel to besuddenly shifted into gear with the relatively stationary wheel.

For the purpose of the invention the wheels of progressively varyingdiameter in.

the respective sets are arranged to form, in effect, toothed cones whoselnclmatlons are opposed to one another; while the relative (or set ofwheels) have one tooth (or toothgap) alined to form a straight rowextending in a plane wherein also lies the common axis of all the wheelsof the set; so that transference of the slidable cone from the positioncorresponding to transmission of motion at one speed-ratio to theposition corresponding to transmission at the next higher orlowerspeed-ratio may be effected, readily and smoothly, when both cones arein that angular position which may (for conveni-ence) be called thetransference position, 75. e. that position wherein the straight row ofteeth and of tooth gaps in the respective cones are simultaneouslybrought, by the revolution of both cones, into what may be termed thetransference plane, z'. e. the common plane of the axes of therespective cones.

V The actual transference movement is effected mechanically, asrequired, through the agency of, means whereby the position andmovements of the slidable cone lengthwise of its shaft are so controlledwith reference to the occurrence of the transference position in thecase of both cones, as to insure that the transference movement can beinitiated only when both cones are simultaneously in the transferenceposition, and that the transference movements, when once initiated,shall be completed. These means comprise a drum (or equivalent rotarymemher) which is caused to rotate about an axis parallel to those of themain shaft and countershaft at the requisite angular velocity, and whichcarries a row of tappets corresponding in number and distance apart tothe number of wheels in each cone and the length of the severalmovements of transference; a carrier engaging the slidable cone andmovable in a direction parallel to the axis thereof so as to be adaptedto impart motion to said cone lengthwise of its shaft; a pair ofoppositely inclined cams mounted on the carrier and normally retained inthe inoperative position but respectively adapted to be brought intoposition to be acted upon by the tappets so as to cause the carrier andcone, according as the one or the other cam is brought into operativeposition, to be shifted in one or the other direction through a distanceequal to the extent of the motion of transference whereby consecutivepairs of change-wheels are brought into operation; and means forenabling either of the cams at will to be moved into and out ofoperative position, but only at the proper moments with reference to thebringing of both cones simultaneously into the transference position.

In the accompanying drawings which illustrate a convenient arrangementembodying the invention (as applied to the variable-speed mechanismemployed in connection with the driving gear of a motor car whereinprovision is made for a direct drive at maximum speed and for reversalof motion at one speed only), Figure 1 is a general plan view of theapparatus, the easing which incloses the same being in section so as todisplay the contents, and the parts being in position for transmittingmotion by direct drive at maximum speed. Fig. 2 is a plan view insection on the common plane of the axes of the main shaft andco-untershaft. Fig. 3 is an inverted plan with the casing broken away,and the camshaft and parts more immediately associated therewithomitted, showing the parts in position for transmitting motion at alower velocity than in Figs. 1 and 2. Fig. 4 is a section on line 4-4:of Figs. 1 and 2, showing one of the cams in operative position andacted upon by one of the tappets. Fig. 5 is an outside end view showing,in normal position, the mechanism for controlling the bringing of thecams into operation. Fig. 6 is a view similar to Fig. 5, showing thesame mechanism in the position occupied when one of the cams is inoperative position. Fig. 7 is a part view similar to Fig. 2, showing amodified construction of reversing mechanism. Figs. 8 and 9 are endviews of the slidable and of the relatively stationary toothed conesrespectively, showing the straight rows of tooth gaps and teeth in therespective cones.

A, B and C are the main shaft, countershaft, and cam shaft respectively,these three shafts being mounted to rotate parallel to one another inbearings provided in the end plates (Z 6Z of the casing D of theapparatus. One end of the main shaft A (in Fig. 2, the left-hand end) ishowever, journaled in a bearing a in the contiguous end of anindependent shaft A which revolves in alinement with the main shaftitself; the shaft A projecting outside the end plate al of the casingand serving to transmit motion to the apparatus from the engine, whilemotion may be transmitted from the shaft A to the main shaft A ashereafter described. The opposite end a of the shaft A projects outsidethe end plate 65 of the easing and serves for transmitting motion to theroad-wheels of the vehicle in any convenient manner.

Fast upon the inner end of the independent shaft A is a toothed pinion Ewhich is permanently in gear with a toothed wheel E fast upon thecountershaft B, so that as long as the shaft A is running, thecountershaft B will revolve at a uniform speed lower than and bearing apredetermined ratio to that of the shaft A Toward the left-hand end(Fig. 2) of the main shaft A a sleeve F is splined thereon, theleft-hand extremity of this sleeve being provided with a clutch-face fadapted to engage a corresponding clutch-face f on the inner end of theindependent shaft A so that as long as the sleeve is in its extremeleft-hand position, the main shaft A (and therefore also the road wheelsof the vehicle) will be driven direct from the engine at maximum speed.The sleeve F has fast upon or integral with it a plurality of toothedwheels (three are shown in the example) F F, F respectively adapted togear with toothed wheels F F, F fast upon or integral with a sleeve Fwhich is free to rotate upon the countershaft B whereon it is confinedagainst longitudinal movement between shoulders constituted on the onehand by the hub of the wheel E and on the other hand by a collar f. Thewheels F F 2 and F severally are of progressively increasing diameter,while the wheels F, F'* and F severally are of reciprocally diminishingdiameter; the respective pairs F F F F and F F eonstituting pairs ofchange-wheels which are capable of being brought into operationalternatively with one another when the clutch F, f is out of gear. Forthis purpose the positions of the respective wheels are such thatcontinued displacement of the sleeve F toward the right in Fig. 2 willfirst disengage the clutch-faces f, f from one another and willthereafter bring the pairs of change-wheels F F, F and F F successivelyinto mesh with one another and vice versa. The means whereby the sleeveF is so controlled as to enable these changes, or any of them, to beproduced auton'iatically when once initiated by a simple manualoperation, will be described hereafter.

The sleeve F* (and therefore also any of the wheels F, F or F) can bethrown into driving engagement with the shaft B by means of a clutchmember G which is splined upon the shaft and which has a clutch face 9on its left-hand end adapted to engage a corresponding clutch-face onthe right-hand end of the sleeve F Hence,

if, while the clutch-faces g g are in engagement with one another,either of the pairs of change-wheels F F, F F or F F is in operativeposition, motion will be transmitted from the constantly runningcountershaft B to the main shaft A at a velocity corresponding to thepair of changewheels which for the time being is in use.- Inasmuch,however, as no pair of changewheels can be in use when the sleeve F isin engagement with the shaft A through the clutch f f, it will beevident that by no possibility can the parts assume a position whereinmotion would be transmitted from the shaft A to the shaft A directly atmaximum speed (through the clutch f f and indirectly at a lower speed(through either of the pairs of change-wheels) simultaneously.

The clutch-memberG is capable of occupying three positionsalternatively, namely, either the extreme left-hand position shown inFig. 2, wherein the clutch-faces g g are engaged with one another so asto permit the transmission of motion from the shaft B to the sleeve F*,and thence to the shaft A (through one or other of the pairs ofchangewheels) in what is assumed to be the forward direction; or anextreme right-hand position wherein the clutchserves to transmit motionto the shaft A in the reverse direction as hereafter described; or aneutral position (intermediate between the other two) wherein the clutchis inoperative.

When motion is to be transmitted in the reverse direction, the shafts Aand B are geared together not directly butthrough the medium of an idlewheel. For this purpose a toothed wheel H fast on the shaft A toward itsright-hand end, gears constantly with an idle wheel H which for the sakeof convenience is mounted to revolve freely upon the shaft G, the idlewheel H receiving motion, when required, from a pinion H carried by andturning as one with the shaft B. The pinion H may, as in Fig. 2, beconstantly in gear with the wheel H, in which case the pinion is mountedto revolve freely upon the shaft B and held against sliding lengthwiseof said shaft, and is provided with a clutch-face h adapted to beengaged by a corresponding clutch-face h on the right-hand end of theclutch;me1nber G, when the latter occupies its extreme righthandposition. Or, the pinion H may, as in Fig. 7 be attached to or integralwith the clutch-member G so as to be slidable therewith lengthwise ofthe shaft B, in which case the pinion H is thrown into mesh with thewheel H only when the clutch-member Gr is in its extreme right-- handposition.

The position of the clutch-member G isand C and having fast on it a forkG which engages a peripheral groove 9 on -shaft A in the reversedirection from the shaft B while motion is being transmitted to theshaft A in the forward direction from the shaft A through the clutch f fmeans are provided for insuring that when the clutch-faces F, f are inengagement, the clutch--member G shall be prevented from assuming theextreme right-hand position or, in other words, that before theclutch-member G, in being moved toward the right ii'rFig. 2, can reachits extreme right-hand position, the sleeve F shall be displaced so fartoward the right as to cause the clutch-faces F, f to become dis engagedfrom one another. For this purpose the manually operable slide-rod J hasfast on it an arm J which has a pin-andslot engagement as at 7' with alever J fulcrumed at 7' to the casing and adapted to contact with theleft-hand face (Fig. 2) of the wheel F This contact is made with thefree end 7' of the lever J which is made of appropriate cam-shape asindicated, the pin-and-slot device j being situated between this freeend 7' and the fulcrum j Hence if the clutch-faces 'f, f and g g beassumed to be respectively in engagement, then any movement of theslide-rod J toward the right (for the purposeof withdrawing theclutch-faces 9' 9 from engagement preparatory to bringing theclutch-member G into position for effecting reversal of motion. of theshaft A?) will produce a magnified movement of the free end j of thelever J and consequently, even before the clutch-member Gr can bebrought to its neutral position, the clutchfaces f, f will have beendisengaged from one another. Similarly, so long as the clutch-faces f fare in engagement, the lever J will be held, by its contact with thewheel F in such a position that the sliderod J will be prevented frombeing moved toward the right even so far as to assume the positioncorresponding to the neutral position of the clutch-member G, which willthus be effectually prevented from being shifted to the positioncorresponding to reversal of the motion transmitted to the shaft A. IInasmuch as the sleeve F* is freely rotatable on the shaft B, it isnecessary that this sleeve and its wheels F, F, F shall be preventedfrom falling out of time with the sleeve F and its wheel F F, F and,vice versa. For this reason, and also in order to avoid shocks when thegearingratio is changed, it is obvious that, at the &

moment of changing gear, that pair of wheels which are passing out ofgear must remain in mesh with one another until the succeeding pair havebegun to gear with one another; such overlapping of the gears being ofcourse only momentary, and the sliding movement of the sleeve F beingperformed as rapidly as is practicable. The

same conditions must also be observed with regard to the change of gearfrom the clutch f, f to the pair of wheels F F and vice versa. To enablethese conditions to be fulfilled, the toothed cone (or set of wheels)carried by each sleeve has one toot-h (or tooth-gap) in each wheel ofthe set alined to form a straight row lying in a plane wherein also liesthe axis of the cone, as indicated at m (Fig. 8) with regard to toothgaps in the cone carried by the sleeve F, and at y (Fig. 9) with regardto teeth on the cone carried by the sleeve F*; the sliding movement ofthe sleeve F being allowed to take place only when both rows 00 and 3/are brought, by the revolution of the respective shafts A and B, intothe common plane 2-z (Fig. 4) of the axes of these shafts. Moreover,each of the clutches y, f and 9 g is a dog-clutch whose members arecapable of becoming mutually engaged only when the respectiveclutchfaees occupy one angular position relatively to one another, theclutch-face f being suitably disposed with reference to the angularposition of the row of tooth gaps a: while the clutchface g is alsosuitably disposed with reference to the angular position of the row ofteeth y. Furthermore, the several wheels carried by each sleeve F and F*are set at such distances apart from one another, relatively to theposition of the clutch-face f when engaged with the clutch-face as toinsure the necessary overlapping of the gears at the moment of changingspeed. Finally, the effective length and proportions of the lever J aremade such that the movement of the slide-rod J from the position shownin Figs. 2 and 3 to positions corresponding to the neutral and reversingpositions of the clutch G must invariably leave one or other of thepairs of change-wheels F F F F F F in engagement with one another.

It will be obvious that, if the numbers of teeth in the respectivewheels of either cone possess a common divisor greater than unity, agreater number of straight rows of tooth gaps or teeth at or y than thesingle row above mentioned will exist in the respective cones. This willafford a correspondingly increased number of opportunities for theconcurrent passage of the rows 00 and 1 through the transference planezz. In such circumstances each clutch P, f and 9 9 may be capable ofcoming into engagement in as many angular positions of the respectivemembers relatively to one another, as there are straight rows of toothgaps or teeth w or g in the cones to which the respective clutchesappertain. In the example illustrated, each cone is understood to havetwo straight rows of tooth gaps or teeth, as indicated in Figs. 8 and 9respectively.

The various positions of the sleeve F are controlled by means of acarrier K mounted to slide on guides K K parallel to the shafts A, B,and C and jawed as at to engage a peripheral groove 7 on the sleeve F,this sleeve (together with the gear-wheels F F F and the clutch-face fparticipating in the movements of the carrier K lengthwise of itsguides. The carrier extends in a general direction tangentially of theshaft C, and is provided with sockets through which a pair of cams L, L*are fitted to slide in a direction perpendicular to the axis of theshaft C. These cams, viewed in the direction in which they are capableof sliding through their sockets in the carrier K, are respectivelyinclined in opposite directions, and are normally both held in a neutralor inoperative position. Either cam L or L* may however be caused atwill to project from its socket toward the axis of the shaft 0 so as tobe presented in position for engagement, at each revolution of saidshaft, by one of a series of tappets C C C, C forming a straight rowwhich projects from and rotates as one with the shaft C.

The result of such engagement of a cam L or L* by any one of the row oftappets is that the carrier K, together with all those parts whichparticipate in its movement, is caused to slide along its guides K K inthe direction determined by that cam which has been brought intooperation, and through a distance equal to the effective length of thecam. The effective length of each cam L and L*, and also the distanceapart of the several tappets C C, must obviously be equal to thedistance between the successive positions which the sleeve F may berequired to assume; while the number of the tappets (in the exampleillustrated, four) must equal the number of such positions.

The cam-shaft C has fast upon it a toothed wheel C which is constantlyin gear with a toothed wheel 13* fast on the shaft 13, and in order thatthe sliding movement of the sleeve F (or in other words, the change ofgear) shall be permitted to occur only when a row of tooth gaps and ofteeth a: and y respectively are both in the transference plane zz, it isimportant that the ratio of gear ing 13* C whereby the shaft B is drivenshall be such that the row of tappets C C will be brought into positionto operate on the cam L or L only when a straight row of tooth gaps andof teeth 02 and y respectively come into engagement with one another.

The mechanism for bringing the cams L and U alternatively into operativeposition comprises a pair of shafts L L extending parallel to the shaftC and rotatably mounted in bearings in the frame; a corresponding pairof radius-arms Z Z of equal length splined upon the respective shaftsand extending in opposite directions therefrom; and a pair of links Z, Zcoupling the respective arms to the rear ends, of the correspond ingcams L, 13*. of the casing the respective shafts L L have fast upon thema pair of radius-arms Z W of equal length which extend parallel to oneanother and are coupled together by a link Z so that, if either shaft berotated through a small angle in one or the other direction, the othershaft will participate in the movement and the arms Z Z will move inopposite directions with the result that the cams L U respectively willbe depressed into and raised out of operative position or vice versa.

As that cam L or L* which has thus been brought into operative positionis acted upon by the tappets C C the carrier K and parts connectedtherewith will slide along the guides K K as already described, and theradius-arms Z Z being coupled to the respective cams, will slide withthe latter along the shafts L L.

It is essential that, when once a cam L or lL has actually begun to beoperated upon by any one of the tappets C 6*, such action should proceedwithout interruption until the change of gear has been fullyaccomplished by the completion of the sliding movement of the sleeve Ffrom its old to its new position. Hence, provision is made for insuringthat either cam L or L* on being brought into operative position beforethe passage of the row of t-appets C 0* past the cams, shall be lockedin that position until the tappets have passed clear of what may becalled the operative arc of their revolution; and it is found convenientto hold both cams locked in the inoperative position except for aninterval (during each revolution of the tappets) corresponding in timeto, but slightly longer than, the passage of the tappets through saidoperative arc. For this purpose the shaft L (but it might obviously havebeen the shaft L has fast on one of its ends a crank-arm M (Figs. 5 and6) whereby to communicate the necessary partial rotary movement to theshaft, this arm carrying a crank-pin m, which may project from bothsides of the arm as indicated. The pin m engages in slots m m in a pairof links M M which extend at approximately right angles to the arm M andare capable of sliding one over the Outside the end plate d i other inparallel planes so as to cause the arm M to move in one direction or theother according as the link h 1 or 3 is brought into operation. Theslots m m extend in opposite directions from the crankpin m which, whenin its normal or mid position (shown in Fig. 5) occupies one end of theslot m and the opposite end of the slot 0721*, the links themselvesunder these circumstances being held locked so that the pin m ismaintained stationary, with the result that the shafts L L cannot rotateand neither of the cams L, L* can be brought into operative position.

The links M M which respectively serve for bringing the cams L, U intooperative position, are actuated only one at a time, that link which forthe time being is not in use being held locked. The links are coupledtogether by a spring N which constantly tends to so move them both as toreverse the direction in which the slots m m extend from the pin m, theconsequence being that if (say) the link M be released from normalposition, this link will be drawn by the spring so as (after taking upthe lost motion allowed by its slotm to shift the pin 7% to the oppositeend of the slot m, as shown in Fig. 6, thus rotating the shafts L L soas to bring the cam L into operative position, as shown in Fig. 4:; Inthis new position the link M (and therefore the pin m) will be retained(the cam L being 'meanwhile held in operative position) until theaction, of the mechamsm has caused the link M (and therefore the pin mand cam L) to be returned and re-locked in normal position. A similarcycle of consequences will ensue if the link M be released from normalposition, except that this link will be moved by the spring N in theopposite direction to the link M with the result that the pin we willlikewise be shifted in the corresponding direction so as now to bringthe cam 11* into operative position, wherein it will be retained untilthe parts have been automatically returned and re-locked in normalposition as before.

The release and return of the links M M from and to normal position iseffected by trip-mechanism under the control of rotary cams revolving inunison with the row of tappets C C the action of the cams rendering itpossible to release either of the links (and therefore to bring intooperative position either of the cams L or If) only during a periodcorresponding to the interval occupied by the tappets in passing throughthe operative arc of each revolution. For this purpose the links M M arecoupled as at 0, 0" to a pair of levers P, 1 which extend, atapproximately right angles to the links (and therefore approximatelyparallel to one another), on

opposite sides of the cam-shaft C at one end of the latter; theselevers, which are fulcrumed to the frame at p, 12* respectively carryinganti-friction rollers P, P"* which are adapted to bear, from oppositedirections, against a cam Q fast on the shaft. The normal position ofthe levers P, P* corresponds to that wherein the rollers P P justcontact with that portion of the cam Q which has the largest radius, andto this position each of said levers is automatically returned by thecam Q after having been released from said pos tion and displaced by theaction of the spring N.

Both levers P and P* (which for convenience may be called main levers)are normally held (by the stress of the spring N) locked in normalposition by the engagement of nibs or trip-noses 29 29 forming shortarms on the respective levers, with stops r r carried by a correspondingpair of locking-levers R, R fulcrumed to the frame at r, 1 so as to becapable of motion in a plane parallel to that wherein the levers P, P*move; the point of contact between each nib and the co-acting stop (solong as the corresponding stop-lever is in normal position) being sosituated with reference to the fulcrums of the corresponding main leverand locking-lever respectively as to prevent displacement of the mainlever from normal position by the stress of the spring N. Hence, unlessthe locking-lever be forcibly displaced, both the main and the locking-lever will tend, under the stress of the spring N, to remain innormal position.

On either locking-lever R or B being displaced, however, (by angularmovement about its fulcrum r or r*), so as to remove the stop r or 4from contact with the nib p or of the corresponding main lever P or P*,the main lever thus released from normal position will be caused by thespring N to swing toward the axis of the shaft C until the roller P or Pcomes in contact wit-h the cam Q, this movement being sufiieient, whenthat portion of the cam which has the least diameter is in operativeposition, to permit of the link M or M being moved so as to bring thecorresponding cam L or L* into operative position. Now, the operativepositions, and relative angular extents, of those portions of the cam Qwhich have the minimum and maximum diameters, correspond respectively tothe operative and inoperative arcs of the revolution of the row oftappets C C Consequently, whichever main lever P or P* has beenreleased, will automatically perform at the proper moments thosemovements from and back to normal position which are required for thepurpose of moving the corresponding cam L or into and out of operativeposition in time with the revolution of the tappets C C or, in otherwords, in time with the simultaneous bringing of the rows of tooth gapsand teeth 09 and 3/ respectively into the transference plane z-.2.

The locking levers R, are displaced alternatively from normal positionso as to unlock the respective main levers P, P by moving, in onedirection or the other, a manually operable trigger-lever T fulcrumed att to the frame. This lever has arms T, T carrying studs t t whichrespectively engage in slots 1, 7 in the stop-levers R, R the lever Tnormally occupying a mid or inoperative position wherein it permits bothlevers R R* to remain in their normal positions, but the pin-and-slotconnection in each case being such that movement of the trigger-lever Tin either direction will displace one (and only one) of the levers R, Rin such manner as to withdraw the corresponding stop 1" or 1' fromcontact with the nib p or 22 The respective locking-levers R, R overliethe corresponding main levers P, P* and carry anti-friction rollers R Rwhich are adapted to bear, from opposite directions, against a cam Sfast on the shaft C alongside of the cam Q. The normal position of thelevers R, 11* corresponds to that wherein the rollers 11- 11 justcontact with that portion of the cam S which has the largest radius, andto this position each of said levers is auto1natically returned by thecam Q after having been displaced from said position (by the action ofthe trigger-lever T) so as to cause the roller R or R to approach theaxis of the shaft C.

It will be seen that, although manual pressure in either direction mayat all times be applied to the lever T while in normal position, thislever will be prevented from moving so as to displace either of thelocking-levers R, R* except at such times as a part of the cam S havinga radius less than the maximum is presented opposite to the roller R orR It will also be seen that neither of the main levers P, P (even ifunlocked by such displacement of the locking-lever R or will be able tomove from normal position except at such times as a part of the cam Qhaving a radius less than the maximum is presented opposite to theroller P or P Hence, by making the cams Q and S of proper form andmounting them on the shaft C in proper angular relation to each otherand to the row of tappets C C'*, it is rendered impossible to bringeither of the camsL or L* into operative position except when thetappets C C are approaching the operative arc of their revolution. Forthis purpose, whereas on the one hand that part of the cam Q which is ofminimum radius is presented to the roller P or P during the entireperiod occupied by the passage of the tappets C C" through saidoperative are, on the other hand that part of the cam S which is ofminimum radius is presented to the roller R or R during only a briefinterval at or just before the commencement of said period.

Moreover, the forms and relative disposition of the respective cams Qand C are made such that, immediately after either of the main levers Por P* has been unlocked and permitted to move from normal position so asto bring the corresponding cam L or If into operative position, thecorresponding locking-lever R or R is quickly restored to normalposition, leaving the main lever P or 1 in its abnormal or activeposition. Hence the stop 1 or 1" now en gages the back of the nib ortrip-nose 79 or 79 with the result that whichever main lever P or P hasmoved (and therefore, also, whichever cam L or L* has been brought intooperative position), willv be prevented from returning to normalposition until after that part of the cam Q, which is of minimum radiushas passed the roller P or P or in other words, until the row of tappetsC C has passed beyond the operative arc of their revolution. Inconsequence of this arrangement, once a movement of transference of thesleeve F (with its wheels F F F has been initiated, such movement willof necessity be completed without interruption, and thus the possibilitywill be entirely prevented of either the clutch f and the pair ofchange-wheels F F or of any two of the pairs of changewheels F F F F, FF remaining simultaneously in gear longer than during the momentaryinterval required for effecting a change of speed ratio.

It will be observed that at each revolution. of the shaft C, the mainlever P or P*, if previously unlocked and brought to operative position,will be automatically restored to and re-locked in normal position. Thisaction will occur, even in the event of the trigger-lever T (whereby thechange of gear was initiated) being held over continuously in onedirection or the other, since-the manual pressure upon the lever Tis'assumed to be elastic or yielding. Hence, even if the lever T be thusheld over, the slidabl'e sleeve F will be moved lengthwise of the shaftA not continuously, but only step-bystep in time with the revolution ofthe shaft G. lv loreover, once the pressure upon the trigger-lever T isrelieved, the sliding movement of the sleeve F will cease automaticallyat the next restoration of the main and locking levers to normalposition, or in other words, next time the shaft C in the course of itsrevolution brings the cams Q and S to the angular position corresponding to such restoration.

The normal position of the lockinglevers R, R may be determined by stopsu, w in contact with which the respective levers may be normallyretained by springs at, 20*. These springs also serve to return thetrigger-lever T to normal position after displacement therefrom ineither direction, the effort exerted by the respective springs beingtransmitted in opposite directions to the lever T through itspin-and-slot connections with the levers R, R

Claims:

1. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, anda set of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirstmentioned set, the one set of wheels having a straight row of teethand the other a straight row of tooth-gaps, comprising respectively onetooth and one tooth-gap of each wheel of the set, extending in a planewherein also lies the common axis of all the wheels of the set.

2. In variable-speed mechanism, the com bination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirstmentioned set, the one set of wheels having a straight row of teethand the other a straight row of tooth-gaps, comprising respectively onetooth and one tooth-gap of each wheel of the set, extending in a planewherein also lies the common axis of all the wheels of the set, andmeans for varying the ratio of transmission by sliding the splined setof wheels lengthwise of its shaft when the straight row of teeth and thestraight row of tooth-gaps are simultaneously in the common plane of theaxes of both sets of wheels.

3. In variable-speed mechanism, the combination of a main shaft and acountershaft mounted to rotate parallel to one another, a set of toothedchangewheels of different diameters mounted to turn together asonefreely upon the counter-shaft, a set of toothed change-wheels splinedupon the main shaft and respectively adapted to gear alternatively withthe wheels of the first-mentioned set, one set of wheels having astraight row of teeth and the other a straight row of tooth-gaps,comprising respectively one tooth and one tooth-gap of each wheel of theset, extending in a plane wherein also lies the common axis of all thewheels of the set, and means for varying the ratio of transmission bysliding the splined set of wheels lengthwise of the main shaft when thestraight row of teeth and the straight row of toothgaps aresimultaneously in the common plane of the axes of both sets of wheels,said means comprising a clutch-member rotatable as one 'with the set ofchangewheels on the counter-shaft, a corresponding clutclrmember splinedon the countershaft, an independent shaft rotatable in alinement withthe main shaft, gearing for maintaining driving connection at a constantvelocity-ratio between the countershaft and the independent shaft, aclutchmember fast on the independent shaft, a correspondingclutch-member movable as one with the setof change-wheels splined on themain shaft, dog-clutch faces on said members adapted to engage with oneanother when, the sets of change-wheels being mutually disengaged, thestraight row of teeth and the straight row of tooth-gaps aresimultaneously in the common plane of the axes of both sets ofchangewheels, gearing for transmitting motion between the main shaft andcounter-shaft in the reverse direction to that transmitted by thechangewheels, and means for bringing said reverse-motion gearing intooperation alternatively both with the clutching of the countor-shaft tothe set of change-wheels carried thereby, and also with the clutching ofthe main shaft to the independent shaft, substantially as described.

4. In variable-speed mechanism, the com bination of a main shaft and acounter-shaft mounted to rotate parallel to one another, a set oftoothed change-wheels of different diameters mounted to turn togetherasone freely upon the counter-shaft, a set of toothed change-wheelssplined upon the main shaft and respectively adapted to gearalternatively with the wheels of the first-mentioned set, the one set ofwheels having a straight row of teeth and the other a straight row oftooth-gaps, comprising respectively one tooth and one tooth-gap of eachwheel of the set, extending ina plane wherein also lies the common axisof all the wheels of the set, and means for varying the ratio oftransmission by sliding the splined set of wheels lengthwise of the mainshaft when the straight row of teeth and the straight row of tooth-gapsare simult-aneously in the common plane of the axes of both sets ofwheels, said means comprising a clutch-member rotatable as one with theset of change-wheels on the countershaft, a corresponding clutch membersplined on the counter-shaft, an independent shaft rotatable inalinement with the main shaft, gearing for maintaining drivingconnection at a constant velocity-ratio be tween the counter-shaft andthe independent shaft, a clutch-member fast on the independent shaft, acorresponding clutchmember movable as one with the set of change-wheelssplined on the main shaft, dog-clutch faces on said members adapted toengage with one another when, the sets of change-wheels being mutuallydisengaged, the straight row of teeth and the straight row of tooth-gapsare simultaneously in the common plane of the axes of both sets ofchange-wheels, a toothed whee] fast on the main shaft, a toothed pinionrotatable freely on the counter-shaft, an idle wheel in gear with saidwheel and pinion, a clutch-member rotatable as one with the pinion, acorresponding clutchmember splined on the counter-shaft and movable asone with the other clutch-me1nber splined on said shaft, a slide-rod forcontrolling the lust-mentioned clutch-members, an arm on said rod, and alever having a pin-and-slot connection with said arm and adapted tocontact with one of the wheels of the set of change-wheels which issplined upon the main shaft, substantially as described.

5. In variable-speed mechanism, the com bination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirst-mentioned set, the one set of wheels having a straight row ofteeth and the other a straight row of tooth-gaps, comprisingrespectively one tooth and one tooth-gap of each wheel of the set,extending in a plane wherein also lies the common axis of all the wheelsof the set, a carrier slidable parallel to the shafts for controllingthe position of the splined set of change-wheels lengthwise of itsshaft, a pair of reversely inclined cams mounted in sockets in thecarrier, a row of tappets for operating upon said cams, spaced apart inaccordance with the respective positions of the splined set ofchange-wheels and rotatable together about an axis parallel to theshafts, gearing for causing the tappets to pass through the operativeare of their revolution with reference to the cams when the straight rowof teeth and the straight row of tooth-gaps are simultaneously in thecommon plane of the axes of both sets of wheels, and means for bringingeither of the cams alternatively at will into position to be operatedupon by the tappets, substantially as described.

6. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirstmentioned set, the one set of wheels having a straight row of teethand the other a straight row of tooth-gaps, comprising respectively onetooth and one tooth-gap of each wheel of the set, extending in a planewherein also lies the common axis of all the wheels of the set, acarrier slidable parallel to the shafts for controlling the position ofthe splined set of change-wheels lengthwise of its shaft, a pair ofreversely inclined cams mounted in sockets in the carrier, a row oftappets for operating upon said cams, spaced apart in accordance withthe respective positions of the splined set of change-wheels androtatable together about an axis parallel to the shafts, gearing forcausing the tappets to pass through the operative arc of theirrevolution with reference to the cams when the straight row of teeth andthe straight row of tootlrgaps are simultaneously in the common plane ofthe axes of both sets of wheels, means for bringing either of the camsalternatively at will into position to be operated upon by the tappets,and means for automatically preventing the withdrawal of either cam fromoperative position so long as a tappet is in operation upon such cam,substantially as described.

7. In variablespeed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed changevvheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirst-mentioned set, the one set of wheels having a straight row ofteeth and the other a straight row of tooth-gaps, comprisingrespectively one tooth and one tooth-gap of each wheel of the set,extending in a plane wherein also lies the common axis of all the wheelsof the set, a carrier slidable parallel to the shafts for controllingthe position of the splined 'set of change-wheels lengthwise of itsshaft,

a pair of reversely inclined cams mounted in sockets in the carrier, arow of tappets for operating upon said cams, spaced apart in accordancewith the respective positions of the splined set of change-wheels androtatable together about an axis parallel to the shafts, gearing forcausing the tappets to pass through the operative arc of theirrevolution with reference to the cams when the straight row of teeth andthe straight row of tooth-gaps are simultaneously in the common plane ofthe axes of both sets of wheels, means for bringing either of the camsalternatively at will into position to be operated upon by the tappets,means for automatically preventing the withdrawal of either cam fromoperative position so long as a tappet is in operation upon such cam,and means for automaticallyreturning each cam to inoperative positionafter it has been operated upon by a tappet, substantially as set forth.

8. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of i toothed change-wheels splined upon the.

other shaft and respectively adapted to gear alternatively with thewheels of the firstmentionedset, the one set of wheels having a straightrow of teeth and the other a straight row of tooth-gaps, comprisingrespectively one tooth and one tooth-gap of each wheel of the set,extending in a plane wherein also lies the common axis of all the wheelsof the vset, a carrier slidable parallel to the shafts of tooth-gaps aresimultaneously in the common plane of the axis of both sets of wheels, apair of rotaryshafts parallel to the axis of the respective sets ofchange-wheels, arms splined on said shafts, links for coupling the armsto the respective cams, mechanism for causing said shafts to turntogether in the same direction, and means for partially roe tating theshafts in either direction at will so as to cause the respective cams tobe brought alternately into operative position, substantially as setforth. I

9. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirstmention-ed set, the one set of wheels having a straight row ofteeth and the other a straight row of toothgaps, comprising respectivelyone tooth and one tooth-gap of each wheel of the set, extending in aplane wherein also lies the common axis of all the wheels of the, set, acarrier slidable parallel to the shafts for controlling the position ofthe splined set of change-wheels lengthwise of its shaft,

a pair ofreversely inclined cams mounted lOQ pass through the operativearc of their revolution with reference to the cams when the straight rowof teeth and the straight row of tooth-gaps are simultaneously in thecommon plane of the axes of both sets of wheels, a pair of rotary shaftsparallel to the axes of the respective sets of change-wheels, armssplined on said shafts, links for coupling the arms to the respectivecams, mechanism for causing said shafts to turn together in the samedirection, an arm M fast on one of said shafts, a crank-pin m on saidarm, a pair of links M M having slots m m engaging said crank-pin, aspring N for connecting said links together, levers P, P* pivotallyconnected to the respective links, a rotary cam Q adapted to engage thelevers, gearing for rotating said cam in time with the revolution of thetappets, means for normally retaining both levers out of the path of thecam Q in opposition to the stress of the spring N, and means forreleasing either lever from normal position at will, substantially asdescribed with reference to the accompanying drawings.

10. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed change-wheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively-adapted to gear alternatively with the wheels ofthefirstmention-ed set, the one set of wheels having a straight row ofteeth and the other a straight row of tooth-gaps, comprisingrespectively one tooth and one tooth-gap of each wheel of the set,extending in a plane wherein also lies the common axis of all the wheelsof the set, a carrier slidable parallel to the shafts for controllingthe position of the splined set of changewheels lengthwise of itsshaft,a pair of reversely inclined cams mounted in sockets in thecarrier, a row of tappets for operating upon said cams, spaced apart inaccordance with the respective positions of the splined set ofchange-wheels and rotatable together about an axis parallel to theshafts, gearing for causing the tappets to pass through the operativearc of their revolution with reference to the cams when the straight rowof teeth and the straight row of tooth-gaps are simultaneously in thecommon plane of the axes of both sets of wheels, a pair of rotary shaftsparallel to the axes of the respective sets of change-wheels, armssplined on said shafts, links for coupling the arms to the respectivecams, mechanism for causing said shafts to turn together in the samedirection, an arm M fast on one of said shafts, a crank-pin m on saidarm, a pair of links M M having slots m m engaging said crank-pin, aspring N for connecting said links together, levers P, 1 pivotallyconnected to the respective links, a rotary cam Q adapted to engage thelevers, means for normally retaining both levers out of the path of thecam Q in opposition to the stress of the spring N, levers R, R, stops r,1 on said levers for normally engaging nibs p, 12 on the respectivelevers P, P a rotary cam S adapted to engage the levers R, Rf, gearingfor rotating the cams Q and S in time with the revolution of thetappets, and means for displacing either of the levers R, R* from normalposition alternatively at will, substantially as described withreference to the accompanying drawings.

11. In variable-speed mechanism, the combination of two rotary shaftsparallel to one another, a set of toothed changewheels of differentdiameters mounted to turn together as one freely upon the one shaft, aset of toothed change-wheels splined upon the other shaft andrespectively adapted to gear alternatively with the wheels of thefirst-mentioned set, the one set of wheels having a straight row ofteeth and the other a straight row of tooth-gaps, comprising respectively one tooth and one tooth-gap of each wheel of the set,extending in a plane wherein also lies the common axis of all the wheelsof the set, a carrier slidable parallel to the shafts for controllingthe position of the splined set of change-wheels lengthwise of itsshaft, a pair of reversely inclined cams mounted in sockets in thecarrier, a row of tappets for operating upon said cams, spaced apart inaccordance with the respective positions of the splined set ofchange-wheels and rotatable together about an axis parallel to theshafts, gearing for causing the tappets to pass through the operativearc of their revolution with reference to the cams when the straight rowof teeth and the straight row of tooth-gaps are simultaneously in thecommon plane of the axes of both sets of wheels, a pair of rotary shaftsparallel to the axes of the respective sets of change-wheels, armssplined on said shafts, links for coupling the arms to the respectivecams, mechanism for causing said shafts to turn together in the samedirection, an arm M fast on one of said shafts, a crankpin m on saidarm, a pair of links M M having slots m m engaging said crankpin, aspring N for connecting said links together, levers P, P* pivotallyconnected to the respective links, a rotary cam Q adapted to engage thelevers, means for normally retaining both levers out of the path of thecam Q in opposition to the stress of the spring N, levers R, stops 1' 1on said levers for normally engaging nibs 72 22 on the respective leversP, P*, a rotary cam S adapted to engage the levers R, R gearing forrotating the cams Q and S in time with the revolution of the tappets,and a manually-operable lever T having a pin-and-slot connection withboth the levers R and 11*, substantially as described with reference tothe accompanying drawings.

12. In variable-speed mechanism, the combination of two rotary membersfor conjointly transmitting motion at variable velocity-ratio, one ofsaid members being slidable, lengthwise of its axis relatively to theother member, for effecting such variation of velocity-ratio, and meansfor producing such sliding movement of said member in either directionat will, comprising a pair of levers, connections between the individuallevers of the pair and the means for producing motion of the slidablemember in oppo site directions respectively, a rotary cam forcontrolling the displacement of said levers from normal position and forautomatically returning them to normal position, a spring for bringingsaid levers into contact with the cam, a second pair of levers fornormally retaining the respective levers of the first-mentioned pair outof contact with the cam, a second cam, rotatable as one with thefirst-mentioned cam, for controlling the displacement of the levers ofthe second pair from normal position. and for automatically returningthem to normal position, springs for bringing the levers of the secondpair into contact with said second cam, manually operable means fordisplacing either lever of the second pair alternatively at will fromnormal position, and gearing for rotating both cams at a speed bearing apredetermined ratio to the angular velocity of the aforesaid slidablemember, substantially as described.

13. In variable-speed mechanism, the combination of two rotary membersfor conjointly transmitting motion at variable velocity-ratio, one ofsaid members being slidable, lengthwise of its axis relatively to theother member, for effecting such variation of velocity-ratio, and meansfor producing such sliding movement of said member in either directionat will, comprising a pair of levers, connections between the individuallevers of the pair and the means for producing motion of the slidablemember in opposite direct-ions respectively, a rotary cam forcontrolling the displacement of said levers from normal position and forautomatically returning them to normal position, a spring for bringingsaid levers into contact with the cam, a second pair of levers fornormally retaining the respective levers of the first-mentioned pair outof contact with the cam, a second cam, rotatable as one with thefirst-mentioned cam, for controlling the displacement of the levers ofthe second pair from normal position and for automatically returningthem to normal position, springs for bringing the levers of the secondpair into contact with said sec- 0nd cam, a manually-operable lever andpinand-slot connections between two of its arms and the respectivelevers of the second pair, for displacing either lever of said pairalternatively at will from normal position, and gearing for rotatingboth cams at a speed bearing a predetermined ratio to the angu-,

lar velocity of the aforesaid slidable member, substantially asdescribed.

14;. In variable-speed mechanism, the com bination of two rotary membersfor conjointly transmitting motion at variable velocityratio, one ofsaid members being slidable, lengthwise of its axis relatively to theother member, for effecting such variation of velocity-ratio, a carriermovable parallel to the axis of the slidable member for controllingtheposition of said member, a pair of reversely inclined cams mounted insockets in the carrier, a row of tappets for operating upon said cams,spaced apart in ac cordance with the respective positions of theslidable member and rotatable together about an axis parallel to that ofsaid member, gearing for rotating said tappets at a predeterminedvelocity-ratio relatively to the angular velocity of the slidablemember, and apparatus for controlling the bringing of said camsalternatively at will into position to be operated upon by the cams,said apparatus comprising a pair of levers, connections between theindividual levers of the pair and the respective cams, a rotary cam forcontrolling the displacement of said levers from normal position and forautomatically returning them to normal position, a spring for bringingsaid levers into contact with the cam, a second pair of levers fornormally retaining the respectivelevers of the firstunentioned pair outof contact with the cam, a second cam, rotatable as one with thefirst-mentioned cam, for con trolling the displacement of the levers ofthe second pair from normal posit-ion and for automatically returningthem to normal position, springs for bringing the levers of the secondpair into contact with said second cam, manually operable means fordisplacing either lever of the second pair alternatively at will fromnormal position, and gearing for rotating both cams at a speed bearing apredetermined ratio to the angular velocity of the aforesaid slidablemember, substantially as described.

15. In variable-speed mechanism,the combination of two rotary membersfor conjointly transmitting motion at variable velocity-ratio, one ofsaid members being slidable, lengthwise of its axis relatively to theother member, for effecting such variation of velocity-ratio, a carriermovable parallel to the axis of the slidable member for controlling theposition of said member, a pair of reversely inclined cams mounted insockets in the carrier, a row of tappets for operating upon said cams,spaced apart in accordance With the respective positions of the slidablemember and rotatable togetherabout an axis parallel to that of saidmember, gearing for rotating said tappets at a arm, a pair of leverscoupled to the respective links a rotar cam for controllin thedisplacement of said levers from normal position and for automaticallyreturning them to normal position, a spring for bringing said leversinto contact with the cam, a second pair of levers for normallyretaining the respective levers of the first-mentioned pair out ofcontact with the cam, a second cam, rotatable as one with thefirst-mentioned cam, for controlling the displacement of the levers ofthe second pair from normal position and for automatically returningthem to normal position, springs for bringing the levers of the secondpair into contact With said second cam, manually operable means fordisplacing either lever oi. the second pair alternatively at will fromnormal position, and gearing for rotating both cams at a speed bearing apredctcrmined ratio to the angular velocity of the aforesaid slidablemember, substantially as described.

RICHARD MATTHEWS BUCK.

lVitnesses GEORGE E. MINTERN,

WILLIAM G. E. DAVIES.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G."

